Expression and localization of five members of the testis-specific serine kinase (Tssk) family in mouse and human sperm and testis

TitleExpression and localization of five members of the testis-specific serine kinase (Tssk) family in mouse and human sperm and testis
Publication TypeJournal Article
Year of Publication2011
AuthorsLi Y, Sosnik J, Brassard L, Reese M, Spiridonov NA, Bates TC, Johnson GR, Anguita J, Visconti PE, Salicioni AM
JournalMolec Hum Reprod
Volume17
Issue1
Pagination42-56
Date Published2011
AbstractMembers of the testis-specific serine/threonine kinases (Tssk) family may have a role in sperm differentiation in the testis and/or fertilization. To gain insight into the functional relevance of these kinases, their expression was examined both at the mRNA and protein levels. Quantitative PCR analysis confirmed that all five Tssk mRNAs are almost exclusively expressed postmeiotically in the testis. Recombinant mouse and human Tssks were cloned and used for validation of an array of commercial and custom-made antibodies against Tssks. Immunolocalization in mouse testis, and in mouse and human sperm, showed that Tssk1, Tssk2, Tssk4 and Tssk6, but not Tssk3, were present in mouse sperm and in germ cells from mouse testis. TSSK1, TSSK2 and TSSK6 were also detected in human sperm, while TSSK3 was absent. In both mouse and human sperm, Tssk1 was partially soluble, while Tssk2, Tssk4 and Tssk6 were insoluble in non-ionic detergents. In vitro recombinant TSSK2 activity assays showed maximum enzymatic activity at 5 mM Mg(2+) and a Km for ATP of ∼10 µM. These, observations together with findings that the Tssk1/Tssk2 double knock-out as well as the Tssk6 null mice are sterile without presenting other detectable defects, suggest that these kinases could be used as targets for male contraception.
DOI10.1093/molehr/gaq071
Alternate JournalMolec Hum Reprod
Refereed DesignationRefereed
PubMed ID20729278